Quote:
Originally Posted by PRejto
Hi Greg,
Your comments are on the money. The blue halos really bother me so I think I ought to try processing again trying decon on the blue before generating the RGB. Do you ever run into issues with decon before combining messing up colour balance? My understanding is that colour balance needs to be done before any non-linear processing. Does decon count as "non-linear?" The focus seemed pretty good and I have consistent FWHM between the two scopes/cameras. But, yes, even so the stars just look a bit fatter from the Trius on the TEC140.
Decon before combining = no issue. Its a trick of the trade I learnt from Marcus Davies. If you have red halos, then decon the red to match the star sizes of the other colours - works like a treat so long as they are not too far away in size from each other.
Getting both cameras on the subject isn't all that hard as the TEC140 is mounted on an Optec Libra ( http://www.pbase.com/prejto/image/155505015).
Thanks for the tip on the TEC180 thermal stability. Yuri published some info on this just yesterday and said that the TEC180 changes 9 microns/degree C and the TEC140 33 microns/degree. That's quite a difference! Nearly 4X worse. One might speculate that the fluorite lens is making the difference.
Peter |
Unfortunately Peter I think you'll find its the Trius. Don't know why it flares so much on the TEC180 but it does. I am assuming it is also doing this with the 140. In my case though it wasn't just the blue. Was there high cloud when you did the blue? If not then it may be the Trius. It doesn't seem to do it with Mike's 12 inch AG or Rays 10 inch Newt but my TEC180 it was hit and miss depending on whether there were bright stars in the FOV.
Richard Crisp made a remark on the FLI site about 5 weeks ago that may be an explanation that oversampling = fat stars and undersampling = pinpoint stars. Or was it the other way round?? For example FSQ 106 images are way undersampled and you get pinpoint stars.
I am using Astrodon Gen 2 which work fine on the same scopes with my FLI cameras.
Yes I saw that post. All the fluorite scopes has really small thermal expansions compared to the ED models. The 110 fluorite was only about 5 microns and the 110ED was 45 - wow what a difference.
Greg.